The Yelp C# Sample Code by Yelp demonstrates how to search a business by location. To experiment with the example, developers can install the NuGet package, open the API with visual studio, build, and debug.
Google has open sourced its Cloud Search Connector SDK. The goal is to ease the search of third-party content and identities within a company. Google originally partnered with around 50 partners around the world to build third-party connectivity for Cloud Search and has now opened up a public SDK.